Groundwater Quality Evaluation and the Validity for Agriculture Exploitation in the Erbil Plain in the Kurdistan Region of Iraq

Abstract

Climate change and the fast growth of industrial and agricultural enterprises can have a negative impact on groundwater quality. The evaluation of groundwater quality is an important issue to determine the suitability of water for agriculture and other purposes in the Kurdistan Region of Iraq. The quality of water is an important indicator for selecting the best Climate Smart Agriculture practices that can be applied in the region. Industrial and agricultural enterprises use massive amounts of groundwater pollutants such as fertilizers and pesticides, especially in the agriculture sectors. Groundwater samples were collected from varying depths of 110 to 200 m for chemical and physical analysis to determine water availability and quality as well as the effect of water use and of drought on groundwater level fluctuation in Erbil City. The analysis includes pH, electrical conductivity, temperature, total dissolved solids, major cations (Ca2+, Mg2+, Na+, K+) and major anions (SO42−, HCO3−, Cl−, CO3−). The high TDS value is founded in the central part of the study area according to groundwater flow which originates from the mountain area toward the center of the plain. The results of the sodium adsorption ratio (SAR) shows that all water well samples are suitable for irrigation which have a low sodium hazard and use on sodium sensitive crops must be cautioned against, and the sodium hazard shows that there is no toxic effect on the plants because all the groundwater samples fall in the standard limits of sodium percent, which is less than 60%. The sodium hazard is low, based on RSC results, because it falls below the standard limit which is less than 1.5 meq/L. All groundwater samples are classified as having excellent-to-good permeability. The classification of the potential salinity of groundwater samples shows that nine water samples are in the class excellent-to-good, three water samples are good-to-injurious, and four samples are injurious-to-unsatisfactory. The water type in the area is mostly sulfate except for three samples, two of which are of the chloride type and the third is bicarbonate.